The Battle of Teutoburg Forest one of Rome’s greatest defeats.

Teutoburg Forest is commonly seen as one of the most important defeats in Roman history, bringing the triumphant period of expansion under Augustus to an abrupt end. The outcome of this battle dissuaded the Romans from their ambition of conquering Germania, and is thus considered one of the most important events in European history.[9] The provinces of Germania Superior and Germania Inferior, sometimes collectively referred to as Roman Germania, were subsequently established in northeast Roman Gaul, while territories beyond the Rhine remained independent of Roman control. Retaliatory campaigns were commanded by Tiberius and Germanicus and would enjoy success, but the Rhine would eventually become the border between the Roman Empire and the rest of Germania. The Roman Empire would launch no other major incursion into Germania until Marcus Aurelius (r. 161–180) during the Marcomannic Wars.[10]

Some of the descendants of the vassal kingdoms, like the Suebi (by suzerainty), that Augustus tried to create in Germania to expand the romanitas and the Empire would be the ones that invaded the Empire in the fourth and fifth centuries.[11][12

A point this Germanic confederation did not get lucky. They were led by Arminius a Germanic born Roman Officer who knew Roman tactics and used this knowledge to incredible effect.

by TheWeirdWoods